I Write These Letters To You
by Pandora of Ithilien
Summary: Gabriel and Castiel can't sever ties cleanly, not after all these centuries. In the end it comes down to a question; can you really turn your back on family?


Disclaimer: Not mine.

A/N: Right, so putting Balthazar in Castiel's canon spot as the angel working with Uriel was mostly so I wasn't using an OC in that spot for this AU. More about that and how it changes things will be explored in later fics, ones not so focused on the Castiel&Gabriel arc.

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><p>After spending a thousand years with someone to talk to, it's not easy for Castiel to adjust to his separation from Gabriel. At first, Castiel is in Hell and looking for Dean, so he has no time to think about it. But once he's on Earth again, with the Winchesters, he can't stop thinking about it.<p>

He shouldn't. They have Seals to protect, and he needs to keep his involvement secret from Uriel and Balthazar. Actually, he doesn't worry much about Balthazar, but Uriel... There's a chance Uriel might try to smite him the second he sees him. So Castiel has more than enough to be concerned about.

But he misses Gabriel. He misses talking to him about their work, about the things they see in their travels. He even misses being teased, or thrown into fiction-based illusions. Especially when he sees the Winchesters together. They're not as close as they've been before, Sam's growing dependence on demon blood and his ties to Ruby driving a wedge between them, but... They're still brothers. They still have that bond. It makes it impossible to forget what Castiel gave up in order to do what he felt he had to.

Gabriel was the one who had the idea of intervening in human affairs; at first Castiel had tagged along on his tricks, until he came up with his own variant on the idea. They still worked together now and then, and talked about what they were doing when they did not. Now, Castiel can't help but reach out with his mind, talking to Gabriel about the things that are happening.

_Did you know Anael Fell? She's a human called Anna now, and it's so strange. I remember her training me, and now she's a young woman who knows nothing. _

_ We lost another Seal today. Maybe you're right after all, but I have to keep trying._

_ It's alarming, really, how much Balthazar reminds me of you. But then, he was one of your auxiliary messengers before we left, I suppose it makes sense. Even so, it's unsettling._

_ Dean is going to try to stop Sam, and I am waiting for Raphael. Gabriel, I don't think that I... I can't fight an archangel. This is a suicide mission and I know it, but I have to do it. Please, say somethi- _

After he comes back, after his Father _brings_ him back, he stops sending the messages. Lucifer's free, the Apocalypse is starting, and he has too much to do to hang onto futile hopes. And besides, he can't stand to keep doing it when silence is the only response that he gets.

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><p>Gabriel hears every thought Castiel sends his way, and he has to force himself not to reply. He's making a point by not talking to Castiel, he's showing him that he does not condone this crazy idea. If Gabriel gives in, then Castiel will get mixed messages.<p>

And then the last Seal is broken. Gabriel knows the second it happens, but he's already expecting it when it does. Because before that, Castiel's voice echoes in his head, and Gabriel is about to reply, to tell Castiel to get the fuck out of there now, _please_, but then...

His brother's voice cuts off mid-word and Gabriel just... His mind goes blank for a second. And then his mind is shouting, even though he knows it's pointless. Raphael has always been efficient, after all, as a healer or as a killer. But he can't help it, he doesn't want this to have actually happened.

_Cassie? Cassie? Come on, answer me, I know I've been a dick, ignoring you, but just... Castiel? __**Castiel!**_

Gabriel doesn't like silence as a general rule – that's part of why he was the Messenger, he likes to talk and he likes to be around humans and their noise. But this silence echoes through his mind in a way that silence never should. For just a second Gabriel wants to throw himself back into the whole mess, just because of this, because Raphael killed the only real brother he's had in so long and he wants revenge...

But only for a moment. Because Raphael is his brother too, and Raphael's not sane anymore, and Father help him, this is why Gabriel wanted to leave in the first place. This is why he wanted Castiel to stay _out_ of the whole Winchester mess. And he was right, like he knew he would be, but in the face of this crushing silence, that doesn't seem to mean a thing.

Gabriel tries to fill it, after that. Even when he starts hearing rumors that Castiel's not dead after all, that he's back, the silence continues. Gabriel doesn't know if that means that the rumors are false or if Castiel's just given up on talking to him, but either way he needs to keep that silence from overwhelming him again. So he starts sending messages to Castiel, even though he never hears anything back. Once he starts, he can't stop.

_Went after a deadbeat dad today. Brings back memories. I didn't kill him, you'll be surprised to hear. Does the kid better if Daddy lives to pay up all the back child support. My resume's going to look like yours if I keep this leaving 'em alive shit up._

_ The pagans are getting restless. Anansi says they're starting to talk about doing something crazy, like trying to stop the Apocalypse. You know, like you. Maybe you should get in touch with them. Or will that get you in trouble with your boys?_

_ I'm sorry about the TV thing, all right? But looking for Dad, Castiel... It's not going to work. You've been doing that on and off since we came down here, you should know by now he's gone and he's not coming back. Can't we just get this over with?_

_ Guess what, Balthazar's death? He faked it. I ran into the guy, and you're right, he is a lot like me. He's sick of the fighting too, and he knows just how to relax. I can see the disapproval on your face now, Cassie, but really, you should be used to me by now._

It's not like he has anything really useful to say, but he tries anyway. Maybe it's guilt, maybe he's just lonely – Balthazar's not bad, but he's not really the best company after an hour or two, they're actually _too much_ alike. Or maybe he just needs his little brother more than he ever noticed.

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><p>Castiel didn't tell Dean and Sam what traveling through time would really do to him. It's not being cut off from Heaven, not really. He's been cut off since before Europe left the Dark Ages, and it's never been a problem before. Of course, it could be that they're deliberately shutting him down now, he doesn't know for sure. What he does know is that his power is fading, and has been ever since they ran into Gabriel. He's finding it harder to do most things; flying, at least, is still as effortless as ever, but that's about the only thing. Flying, and hearing his brothers and sisters. Hearing Gabriel.<p>

Gabriel is finally speaking to him. But Castiel refuses to answer. He can't get his hopes up only to have them dashed once again. So he pretends he can't hear, ignoring even the apologies that ghost through his mind and his Grace, because words mean nothing now. There's no room left for more words, only for actions. So far, Gabriel's actions have not done him credit, as far as Castiel is concerned.

So, with all of this weighing on him, Castiel keeps one more thing to himself; the fact that he knows, the second he returns from the past, that the damage is as bad as he'd originally expected. He's barely conscious when he arrives, and it's not long before the blackness claims him. When he wakes again, briefly, he panics; in his current state he can't hide himself from the Host.

Which means that Dean and Sam, asleep on the other bed, are in danger while he's with them. Castiel gathers up what strength he has and flies from there, landing hard on a carpeted floor. He's in the old safe house, the one he and Gabriel found and set up in the Scottish Highlands... Had it been the 1500s? Castiel thinks so, but he can't remember exactly. For some reason this bothers him; usually it isn't a challenge to remember simple facts like that, but the truth is that his head is spinning and his vision is going gray and he can't think at all.

All he can do, as he slips back into unconsciousness, is to call for the only person other than the Winchesters that he wishes he could be with, when he knows he's fading away.

_Gabriel?_

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><p>Gabriel arrives in the old safe house to find his little brother spread-eagled on the floor, breathing far, far too shallowly and blood oozing from his nose. It's a good thing he reacts on his feet, even when his mind's grinding to a halt, because he snaps his fingers and Castiel is lying on a bed that wasn't there two seconds ago. Gabriel's across the room before he notices himself taking a step, sitting on the edge of the bed and looking his brother over. He's not even sure where to start – once, long ago, Raph had insisted on sitting the other three archangels down and teaching them to heal, just in case. Gabriel had picked it up better than Mike and Luc, but...<p>

It's not as though Raphael's an option here, of course. Whatever's happened, Gabriel has to fix it himself, because his brother's slipping away and that is not acceptable.

This is the Winchesters' fault. It has to be, in Gabriel's mind, because if not... Castiel's his little brother, and he's not helpless but Gabriel's still supposed to watch out for him. So if it's not the Winchesters' fault then it has to be his, and he can't think that right now.

But as he's examining Castiel's Grace, even as he focuses on repairing the damage wrought by a serious overextension of his power, it stops being just about denial, his anger at the Winchester brothers. Because this should not have happened. Castiel should have been able to time-travel – the reason for all this is in his brother's mind – without damage like this, even now that Heaven is intentionally trying to cut him off. But Castiel's Grace is fading, and Heaven can't do that. What the fuck is going on here?

He pushes the questions aside when Castiel stirs, blue eyes only half-focused. "Gabriel? You actually... You answered me." He sounds surprised and that's almost worse than seeing him like this.

"Hush, Cassie. You scared the shit out of me, little brother. What were you thinking?"

"You tell me to hush and then ask me a question. You don't make sense, Gabriel."

"Was that actually sarcasm? You have been hanging around those chuckleheads for too long."

"Or you," Castiel mumbles. "I'm... surprised you came."

"What is that supposed to mean?" So they haven't been on the best terms, but at a time like this, did he really think...?

"We've barely spoken since I left to find Dean and raise him, and never at the same time, in our minds. And the last time we actually met... was hardly pleasant." An empty pocket dimension, the brothers screaming at each other with their vessels' voices but also with their Grace, their wings and everything about them, physical and true-form. No, it hadn't been pleasant at all. It had been like a tiny version of the prelude to the Fall.

Still, Gabriel shakes his head. "So you figured I'd actually just let you die, is that it?"

"You did tell me not to 'come crawling back' to you, if you remember."

"If I hadn't shown up when I did, the side effects of time travel with your Grace fading like it is – and what is with that, Castiel, for Dad's sake? – would have killed you. No question, and no third chance unless Daddy's feeling generous again. I was mad at you, Cassie, but... You already died once, I wasn't so mad that I'd want to lose you like that again." He stops, because he has to, but the way Castiel is looking at him, with his eyes wide, so surprised, makes him angry all over again. And since he's already beating himself up enough... New target. And he's got an old, familiar one.

"I didn't have a choice, Anael was going to destroy Sam. I couldn't let her do that." He says it matter-of-factly, in a voice that is still far too tired for Gabriel's liking, and it doesn't lessen his fury at all.

"Yeah, just another thing you've done for those assholes? Why didn't they try to help you?"

"They couldn't, and you know that," Castiel points out quietly. "And besides, they... I let them think it was less serious than it turned out to be. Why tell them, they couldn't help."

And knowing Castiel, he probably had those idiots leave him alone before fumbling his way here, which means... If they care at all, they'll probably flip out when they realize he's gone. And from the cold threat in Dean's eyes when he demanded that Gabriel give Castiel back, during the TV Land incident, maybe they do.

And so... "You're an idiot," Gabriel tells his brother firmly.

"I don't have an argument for that. Gabriel... Thank you. But I... I should go back to the Winchesters, before I give in and start asking you for help that you won't give."

Castiel tries to sit up, but Gabriel pushes him back down again. The fact that Castiel doesn't try again only displays how tired he must still be. "Don't even start, all right? You're staying right here. And I need to think." Gabriel gets up and walks to the window, looking out at the moor. It's a view he's seen countless times in the past five hundred-odd years, comforting in its familiarity.

The trouble here is, Sam Winchester was on to something when he wanted to get Gabriel on their little anti-Apocalypse team. Gabriel does like Earth, he's definitely a hedonist, and as irritating as they can be, as disgusting as some of them are, he's gotten pretty damn fond of humanity. There's a lot in them worth protecting. He doesn't want the Apocalypse, he never really did, whatever he claimed. What Gabriel wants, what he's wanted since Lucifer first challenged their Father, is for the fighting to _stop_, whatever that ends up meaning.

He checks on Castiel again, and his brother's sleeping. Normally, angels don't sleep, and it only reminds Gabriel of the other issue here. It was easy enough to make himself forget what was going on with Castiel when he couldn't see him. But now... Now it's harder. Castiel's losing his Grace but still trying to fix this mess, working alongside a pair of fucked-up humans just crazy enough to think they have a shot at defying fate.

Gabriel is sure their ragged little trio can't pull it off. He doubts they can pull it off even if he adds his not-inconsiderable power to the fight. But...

He can't turn his back on Castiel, not again.

So, when his brother wakes up, they'll go see his human buddies. And... Work it out from there. It's the best Gabriel's got right now.


End file.
